<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>水平垂直居中_text-align+vertical-align</title>
</head>
<style>
    .outer{
        width: 300px;
        height: 300px;
        background-color: gray;
        text-align: center;
        line-height: 300px;
    }

    .inner{
        width:100px;
        height:100px;
        background-color:pink;
        display: inline-block;
        vertical-align: middle;
    }
</style>
<body>  
    <div class="outer">
        <div class="inner"></div>
    </div>
</body>
</html>